I've done something similar where I've used the SpatialRelator (Intersects) and then a pythonCaller to do a connected component analysis of the resulting lists, and assign the resulting group id to each feature.
Avoiding Python, you could use a dissolver (Drop Incoming Attributes_, counter (to get a unique id per group) and then a spatialFilter (Merge Attributes) with the dissolved features as filters and original features as candidates.
A bufferer before the dissolver would give you the dark blue result.
Hello @jdh
Thanks alot for trying to point me to the right direction. I am not familiar with python so I will try your suggestion with the disslover, spatialFilter and bufferer.
There is a custom transformer on the hub - ListCombiner - that may help you to create your groups once you have lists.
So if you use a spatial relator and send your buildings in as both requestor and supplier and build a list of related ids, you can then use list combiner which would assign the same group id to all buildings that touch

There is a custom transformer on the hub - ListCombiner - that may help you to create your groups once you have lists.
So if you use a spatial relator and send your buildings in as both requestor and supplier and build a list of related ids, you can then use list combiner which would assign the same group id to all buildings that touch

Why am I not surprised that @takashi has a custom transformer that does exactly what's needed.
This is a generalized case of the connected component analysis I mentioned in my answer.
There is a custom transformer on the hub - ListCombiner - that may help you to create your groups once you have lists.
So if you use a spatial relator and send your buildings in as both requestor and supplier and build a list of related ids, you can then use list combiner which would assign the same group id to all buildings that touch

Thanks alot @ebygomm ! This looks exactly what I am after. Do you think adding a bufferer @jdh was talkiing about would determine No. of group id:s?
There is a custom transformer on the hub - ListCombiner - that may help you to create your groups once you have lists.
So if you use a spatial relator and send your buildings in as both requestor and supplier and build a list of related ids, you can then use list combiner which would assign the same group id to all buildings that touch

Hello, I wounder what type of parameter settings you used in the SpatialRelator and ListCombiner transformers to get the sorted _group_id:s?
Hello, I wounder what type of parameter settings you used in the SpatialRelator and ListCombiner transformers to get the sorted _group_id:s?
Hi @kidega I created a unique ID on every input feature with a Counter, then used the Spatial Predicates "Requestor Intersects Supplier" and "Requestor Touches Supplier" in the SpatialRelator, and in the ListCombiner I set the Source List to that unique ID from the list.
Hi @kidega I created a unique ID on every input feature with a Counter, then used the Spatial Predicates "Requestor Intersects Supplier" and "Requestor Touches Supplier" in the SpatialRelator, and in the ListCombiner I set the Source List to that unique ID from the list.
Hi @danatsafe Thanks for explaining, now I got it working!